A "watchdog" query? That's a new one to me. "We won't fix it, but we'll have something that tells us when something may be amiss". I can't wait to log onto incompetent.com to check my balances on April 1. (The domain appears to be available).
We have a few of those at work. If you are aware of a known bug that would be too difficult to fix, but you have a way of finding out when that bug occurred and the data can be fixed after the fact, you periodically generate a report of when that occurred so you can fix it after the fact.
Yes, it is better if the error doesn't occur, but sometimes fixing the bug is too complicated or the bug resides in a vendor's product so you aren't allowed to touch it.